Grammatik Rechtschreibung is an Android app developed by Marvin Rembrink that aims to help users learn German grammar easily. The app offers a wide range of grammar exercises covering important topics such as spelling, comma placement, and active and passive voice. It is suitable for all learning levels, including A1, A2, B1, B2, and C1, and does not require an internet connection to use.

One of the best features of Grammatik Rechtschreibung is its automatic correction and solution system, which allows users to check their answers and learn from their mistakes. The app covers all the essential topics, including comma placement, capitalization, and the subjunctive. Additionally, if users feel that any topic is missing, they can contact the developer via email and request it to be added.

Overall, Grammatik Rechtschreibung is an excellent app for anyone looking to improve their German grammar skills. It is easy to use, informative, and accessible. With its vast range of exercises and automatic correction and solution system, users can learn German grammar at their own pace and convenience.